CrackCrack is a freebase form of cocaine. To turn cocaine to crack, it is processed with baking powder, and the result is a solid, smokable form of cocaine. Smoking crack cocaine is highly addictive, making a crack cocaine addiction a foregone conclusion.

i smoked crack and 7 days later failed a instant detection drug test. They are sending the urine to a lab for verification but because of long weekend it will take 4 days to test. Will my urine still fail?

It strikes me as odd that you came up positive seven days out, all my info states dip-sticks are good for 3-5 days. as far as the sate of your urine being two weeks old, once those metabolites leave the body they are what they are.
Oh and the dip-stick...I tested positive, falsly, it happens. The lab confirmed my story. good luck.